The construction of a chimpanzee enclosure at Twycross Zoo was one of our more unusual projects. The design was dictated by specific needs, particularly with regards to security.

The new enclosure has several different areas, each tailored to specific care for the chimps. There are two main habitat areas, each seven metres high to promote free movement and natural behaviours. In addition, there are five management cages, three research and test areas, and additional internal caging. Sliding doors have multiple operational options, both automated and able to be controlled from outside the enclosure/caging areas. High-level keeper walkways give clear sight lines and facilitate feeding of the chimps. The habitat areas also incorporate biopits, 1.5m below the ground slab level — these are filled with pine chips to break down the chimps’ waste. Internal lighting and heating are controlled remotely with a building management system.

Visitors view the chimps through glazed screens which face onto both the internal and external habitats. The visitor corridor that houses these viewing screens is finished with jungle theming – vines, tree trunks, walkways, and artworks etc. The external habitat is a secure enclosure with dry moats, climbing structures and planting; the chimps reach the outside through a series of tunnels linked to the indoor habitat. Constructed from six-metre-high precast concrete walls, the external area is completely secure whilst also being stimulating for the chimps. An illusion of extra depth is created with some of the walls being partially sunken to facilitate viewing.

The whole site is kept liveable through all weathers by the drainage systems. Both foul and storm drainage is installed to discharge into existing site drainage systems, while surface water drainage goes to a newly formed swale which in turn filters into the ground.